6 days missing from 10-day forecast

I'm using an Anvil developer subscription and I'm trying to get a 10-day forecast for Paris. However, I see 6 days are missing from the simpleforecast data. As you can see, August 30 through September 4 are missing.

I use /forecast10day/ and I only get 7 or 8 days of data with the 8th day only having partial data if it has any at all.
Is this a bug or is it just due to /forecast10day/ lacking a way to inform the user that data only exists for those 7 or 8 days.